Variable area fan nozzle and thrust reverser

ABSTRACT

A nozzle for use in a gas turbine engine includes a nozzle door having a first end, a second end opposed from the first end, and a first pivot on the door between the first and second ends. A linkage connects to the nozzle door and to an actuator. The actuator is selectively operative to move the linkage about a second pivot to in turn move the nozzle door about the first pivot between a plurality of positions, such as stowed, intermediate, and thrust reverse positions to influence bypass airflow through a fan bypass passage. A lip extends from the nozzle door between the first pivot and one of the first end and second end.

This application is a divisional of U.S. application Ser. No. 13/238,028filed on Sep. 21, 2011, now U.S. Pat. No. 8,418,436, which is acontinuation of U.S. application Ser. No. 11/693,096 filed on Mar. 29,2007, now U.S. Pat. No. 8,127,529.

BACKGROUND OF THE INVENTION

This invention relates to gas turbine engines and, more particularly, toa gas turbine engine having a variable fan nozzle integrated with athrust reverser of the gas turbine engine.

Gas turbine engines are widely known and used for power generation andvehicle (e.g., aircraft) propulsion. A typical gas turbine engineincludes a compression section, a combustion section, and a turbinesection that utilize a primary airflow into the engine to generate poweror propel the vehicle. The gas turbine engine is typically mountedwithin a housing, such as a nacelle. A bypass airflow flows through apassage between the housing and the engine and exits from the engine atan outlet.

Presently, conventional thrust reversers are used to generate a reversethrust force to slow forward movement of a vehicle, such as an aircraft.One type of conventional thrust reverser utilizes a moveable door stowednear the rear of the nacelle. After touch-down of the aircraft forlanding, the door moves into the bypass airflow passage to deflect thebypass airflow radially outwards into cascades, or vents, that directthe discharge airflow in a forward direction to slow the aircraft.Although effective, this and other conventional thrust reversers serveonly for thrust reversal and, when in the stowed position fornon-landing conditions, do not provide additional functionality. Thelimited functionality and the weight that a conventional thrust reverseradds to the engine contribute to engine inefficiency. Therefore, inorder to improve engine efficiency, there is a need for a system havinga thrust reverser that is integrated with at least one other enginesystem for additional functionality outside of landing.

SUMMARY OF THE INVENTION

An example nozzle for use in a gas turbine engine includes a nozzle doorhaving a first end, a second end opposed from the first end, and a firstpivot on the door between the first end and the second end. A linkageconnects to the nozzle door and to an actuator. The actuator isselectively operative to move the linkage about a second pivot to inturn move the nozzle door about the first pivot between a plurality ofpositions, such as a stowed position, an intermediate position, and athrust reverse position, to influence a bypass airflow through a fanbypass passage. The fan bypass passage has a radially outward sidedefined by a nacelle in at least one position. At least a portion of thenozzle door is radially outward of the nacelle and the nozzle doorincludes a lip that extends from the nozzle door between the first pivotand one of the first end and the second end.

Another example nozzle includes a nozzle door having a first end, asecond end opposed from the first end, and a first pivot on the doorbetween the first end and the second end. A linkage connects to thenozzle door and to an actuator. The actuator is selectively operative tomove the linkage about a second pivot to in turn move the nozzle doorabout the first pivot between a plurality of positions, such as a stowedposition, an intermediate position, and a thrust reverse position, toinfluence a bypass airflow through a fan bypass passage. The linkage andthe nozzle door rotate in the same direction and the nozzle doorincludes a lip that extends from the nozzle door between the first pivotand one of the first end and the second end.

In one example, the stowed position corresponds to an aircraft take-offcondition, the intermediate position corresponds to an aircraft cruisecondition, and the thrust reverse position corresponds to an aircraftcondition after landing.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows.

FIG. 1 illustrates selected portions of an example gas turbine enginesystem having a nozzle that integrates functions of a variable fannozzle and a thrust reverser.

FIG. 2 is a schematic view of an example nozzle door in a stowedposition.

FIG. 3 is a schematic view of the example nozzle door in a thrustreverse position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a schematic view of selected portions of an examplegas turbine engine 10 suspended from an engine pylon 12 of an aircraft,as is typical of an aircraft designed for subsonic operation. The gasturbine engine 10 is circumferentially disposed about an enginecenterline, or axial centerline axis A. The gas turbine engine 10includes a fan 14, a low pressure compressor 16 a, a high pressurecompressor 16 b, a combustion section 18, a high pressure turbine 20 b,and a low pressure turbine 20 a. As is well known in the art, aircompressed in the compressors 16 a, 16 b is mixed with fuel that isburned in the combustion section 18 and expanded in the turbines 20 aand 20 b. The turbines 20 a and 20 b are coupled for rotation with,respectively, rotors 22 a and 22 b (e.g., spools) to rotationally drivethe compressors 16 a, 16 b and the fan 14 in response to the expansion.In this example, the rotor 22 a also drives the fan 14 through a geartrain 24.

In the example shown, the gas turbine engine 10 is a high bypass gearedturbofan arrangement. In one example, the bypass ratio is greater than10:1, and the fan 14 diameter is substantially larger than the diameterof the low pressure compressor 16 a. The low pressure turbine 20 a has apressure ratio that is greater than 5:1, in one example. The gear train24 can be any known suitable gear system, such as a planetary gearsystem with orbiting planet gears, planetary system with non-orbitingplanet gears, or other type of gear system. In the disclosed example,the gear train 24 has a constant gear ratio. Given this description, oneof ordinary skill in the art will recognize that the above parametersare only exemplary and that other parameters may be used to meet theparticular needs of an implementation.

An outer housing, nacelle 28, (also commonly referred to as a fannacelle) extends circumferentially about the fan 14. A generally annularfan bypass passage 30 extends between the nacelle 28 and an innerhousing, inner cowl 34, which generally surrounds the compressors 16 a,16 b and turbines 20 a, 20 b.

In operation, the fan 14 draws air into the gas turbine engine 10 as acore flow, C, and into the bypass passage 30 as a bypass air flow, D. Inone example, approximately 80 percent of the airflow entering thenacelle 28 becomes bypass airflow D. A rear exhaust 36 discharges thebypass air flow D from the gas turbine engine 10. The core flow C isdischarged from a passage between the inner cowl 34 and a tail cone 38.A significant amount of thrust may be provided by the bypass airflow Ddue to the high bypass ratio.

The example gas turbine engine 10 shown FIG. 1 also includes a nozzle 40(shown schematically) associated with the bypass passage 30. In thisexample, the nozzle 40 is coupled with the trailing edge of the nacelle28.

The nozzle 40 includes actuators 42 for movement between a plurality ofpositions to influence the bypass air flow D, such as to manipulate anair pressure of the bypass air flow D. A controller 44 commands theactuators 42 to selectively move the nozzle 40 among the plurality ofpositions to manipulate the bypass air flow D in a desired manner. Thecontroller 44 may be dedicated to controlling the actuators 42 andnozzle 40, integrated into an existing engine controller within the gasturbine engine 10, or be incorporated with other known aircraft orengine controls. For example, selective movement of the nozzle 40permits the controller 44 to vary the area of the nozzle 40 for variousconditions, enhance conditions for aircraft control, enhance conditionsfor operation of the fan 14, or enhance conditions for operation ofother components associated with the bypass passage 30, depending oninput parameters into the controller 44.

In one example, the gas turbine engine 10 is designed to operate withina desired performance envelope under certain predetermined conditions,such as cruise. For example, it is desirable to operate the fan 14 undera desired pressure ratio range (i.e., the ratio of air pressure forwardof the fan 14 to air pressure aft of the fan 14) to avoid fan flutter.To maintain this range, the nozzle 40 influences the bypass airflow D tocontrol the air pressure aft of the fan 14 and thereby control thepressure ratio. For example, for a cruise condition, the nozzle 40permits less bypass airflow D, and in a take-off condition the nozzlepermits more bypass airflow D. In some examples, the nozzle varies across-sectional area associated with the bypass passage 30 byapproximately 20% to increase the bypass airflow D for take-off. Thus,the nozzle 40 enables the performance envelope to be maintained over avariety of different flight conditions.

FIGS. 2 and 3 illustrate selected positions of an example nozzle 40. InFIG. 2, the nozzle 40 is in a cruise position, but may be moved to atake-off position or thrust reverse position. In FIG. 3, the nozzle isin the thrust reverse position to slow forward movement of an aircraft.

In the disclosed examples, the nozzle 40 includes a plurality of nozzledoors 54 (one shown) located circumferentially about the trailing end ofthe nacelle 28. Each of the nozzle doors 54 includes a first end 54 a, asecond end 54 b opposed from the first end, and a pivot 56 locatedbetween the ends 54 a and 54 b. The nozzle door 54 is rotatable aboutthe pivot 56 between the cruise position and the thrust reverseposition. The nozzle 40 is also pivotable about a hinge point 59 to movethe end 54 b of the nozzle 40 along direction 61 between the cruiseposition and a take-off position, as will be described below.

A lip 57 extends from the nozzle door 54 between the pivot 56 and thefirst end 54 a. The lip 57 may be integrally formed with the nozzle door54, or a separate piece that is attached to the nozzle door 54 in aknown manner.

A frame 58 is pivotally secured to the trailing end of the nacelle 28 athinge point 59 and supports the nozzle door 54 at the pivot 56. Theframe 58 includes multiple slots 60 (one shown) that slidingly receive afirst link 62 of a linkage 64 that connects the nozzle door 54 with theactuator 42. The first link 62 includes an end section 68 a that issecured to the nozzle door 54 and another end section 68 b that issecured with a an actuator rod 70. In this example, the end section 68 aextends in a lengthwise direction along axis L₁ (FIG. 3) and the endsection 68 b extends in a lengthwise direction along axis L₂, which istransverse to L₁. The actuator rod 70 is pivotally connected at one endwith the end section 68 b of the first link 62 and at the other end witha trunnion pivot 72 to the actuator 42. In one example, the trunnionpivot 72 is shimmed to allow adjustment of the linkage 64, such asadjustment for wear after a period of usage or adjustment for finetuning the movement of the nozzle door 54.

The frame 58 also includes openings 66, or vents, that each open on oneend 66 a to the bypass passage 30 and on another end 66 b to the outersurroundings of the engine 10. When the nozzle door 54 is in the cruiseposition, the nozzle door 54 abuts the ends 66 b such that the openings66 become blind and are open only on the end 66 a facing the bypasspassage 30. Each of the openings 66 includes a corresponding lengthextending between the end 66 a and the nozzle door 54. In one example,one or more of the openings 66 are designed with lengths that correspondto an acoustic characteristic of the bypass airflow D through the bypasspassage 30. The acoustic characteristic, such as an acoustic frequencyor acoustic amplitude, can be determined or estimated in a known mannerusing experimental measurements, computer simulation, or other knowntechnique. For example, the lengths are designed such that acousticenergy carried by the bypass airflow D reflects within the openings 66and thereby acoustically cancels to provide a benefit of soundattenuation.

The controller 44 commands the actuator 42 to move the nozzle 40 betweenthe take-off position, cruise position, and thrust reverse position,depending on aircraft conditions. The aircraft conditions may bedetermined using known parameters, such as rotor 22 a or 22 b speed,aircraft speed, sensing a weight on an aircraft landing gear, etc.

In one example, the controller 44 moves the nozzle 40 between thetake-off condition and the cruise condition nozzle 40 to change across-sectional area, AR (FIG. 2), which corresponds to thecross-sectional area of the annular bypass passage 30 adjacent thenozzle 40. The controller 44 selectively commands the actuator 42 tomove the nozzle 40 and thereby change the cross-sectional area AR toinfluence the bypass airflow D in a desired manner, depending on theaircraft conditions (e.g., take-off, landing, and cruise). That is, thecontroller 44 moves the nozzle 40 to a cross-sectional area AR that isdesired for the aircraft condition.

For example, moving the nozzle to a relatively smaller overallcross-sectional area for aircraft cruise (FIG. 2) would restrict thebypass airflow D and produce a pressure build-up (i.e., an increase inair pressure) within the bypass passage 30. Moving the nozzle 40 to arelatively larger cross-sectional area for take-off (i.e., pivoting thenozzle 40 about hinge point 59 such that the end 54 b moves outwardsfrom centerline axis A) permits more bypass airflow D and reduces thepressure build-up (i.e., a decrease in air pressure). Thus, depending onthe input parameters into the controller 44, the controller 44 commandsthe actuator 42 to move the nozzle doors 54 to a desired position tocontrol the bypass airflow D in a desired manner.

To move the nozzle 40 between the take-off position and the cruiseposition, the actuator 42 moves the actuator rod 70 (i.e., either to theleft or to the right in Figures), which in turn moves the first link 62along the slot 60. When the first link 62 encounters the end of the slot60, the nozzle 40 will be forced to pivot about hinge point 59, therebychanging the cross-sectional area AR. As can be appreciated, the amountthat the nozzle 40 pivots depends on the amount that the actuator 42moves the actuator rod 70.

To move the nozzle door 54 to the thrust reverse position, the actuator42 retracts the actuator rod 70 (i.e., to the left in figures). Movementof the actuator rod 70 causes the first link 62 to pivot (clockwise inFIG. 3) about the pivot connection 71 within the slot 60 such that thefirst link 62 pivots the nozzle door 54 about pivot 56 (clockwise inFIG. 3) to the intermediate or thrust reverse position. Likewise, theactuator 42 extends the actuator rod 70 to pivot the nozzle door 54 inthe opposite direction.

In the thrust reverse position, the nozzle door 54 extends radiallyoutwards from the nacelle 28 and radially inwards from the nacelle 28into the bypass passage 30. In the illustrated example, the nozzle door54 is pivoted until the second end 54 b of the nozzle door 54 abuts theinner cowl 34. Movement of the nozzle door 54 to the thrust reverseposition opens an auxiliary passage 80 for discharge of the bypassairflow D in a forward direction 82 (relative to movement of the engine10). The second end 54 b of the nozzle door 54 deflects the bypassairflow D radially outwards through the openings 66. In one example, theopenings 66 are angled or curved forward to turn the airflow forward.The lip 57 additionally deflects the airflow forward to slow forwardmovement of the aircraft.

The disclosed example nozzles 40 thereby integrates the functions ofvarying the cross-sectional area of the bypass passage 30 to influencethe bypass airflow D in a desired manner and thrust reversal for slowingforward movement of an aircraft. Although a preferred embodiment of thisinvention has been disclosed, a worker of ordinary skill in this artwould recognize that certain modifications would come within the scopeof this invention. For that reason, the following claims should bestudied to determine the true scope and content of this invention.

We claim:
 1. A nozzle for use in a gas turbine engine, comprising: anozzle door having a first end, a second end opposed from the first end,and a first pivot on the door between the first end and the second end;a linkage connected with the nozzle door; and an actuator coupled withthe linkage, wherein the actuator is selectively operative to move thelinkage about a second pivot to in turn move the nozzle door about thefirst pivot between a plurality of positions to influence a bypassairflow through a fan bypass passage having a radially outward sidedefined by a nacelle in at least one position, wherein at least aportion of the nozzle door is radially outward of the nacelle, whereinthe nozzle door includes a lip that extends from the nozzle door at alocation between the first pivot and one of the first end and the secondend, wherein the actuator is configured to retract an actuator rod tomove the nozzle door towards a thrust reverse position.
 2. The nozzle asrecited in claim 1, wherein the linkage is connected to the nozzle doorbetween the first pivot and one of the first end or the second end. 3.The nozzle as recited in claim 1, wherein the lip extends from thenozzle door in an axially forward direction relative to the bypassairflow.
 4. The nozzle as recited in claim 1, wherein the nozzle doormoves between a stowed position, an intermediate position, and thethrust reverse position to influence the bypass airflow.
 5. The nozzleas recited in claim 1, wherein the linkage includes an end that movesparallel to the actuator.
 6. The nozzle as recited in claim 1, whereinthe actuator is pivotably connected to the linkage.
 7. The nozzle asrecited in claim 1, wherein a plurality of additional nozzle doors eachhaving a first end, a second end opposed from the first end, and a firstpivot on the door between the first end and the second end are connectedto a respective linkage, wherein each linkage is coupled to a respectiveactuator.
 8. The nozzle as recited in claim 1, wherein a controllercommands the actuator to selectively move the linkage.
 9. The nozzle asrecited in claim 1, wherein the lip is formed independent from thenozzle door and attached to the nozzle door.
 10. The nozzle as recitedin claim 1, wherein the nozzle door is supported by a frame member,wherein the frame is pivotally secured to an aftmost end of the nacellerelative to the bypass flow.
 11. The nozzle as recited in claim 1,wherein the linkage and the nozzle door rotate in the same direction.12. The nozzle as recited in claim 1, wherein the lip is disposed at anon-parallel angle relative to the nozzle door when the nozzle door isin a thrust reverse position.
 13. A nozzle for use in a gas turbineengine, comprising: a nozzle door having a first end, a second endopposed from the first end, and a first pivot between the first end andthe second end; a linkage connected with the nozzle door; and anactuator coupled with the linkage at a linkage end, wherein the actuatoris selectively operative to move the linkage about a second pivot to inturn move the nozzle door about the first pivot between a plurality ofpositions to influence a bypass airflow through a fan bypass passage,wherein the linkage and the nozzle door rotate in the same direction,wherein the nozzle door includes a lip that extends from the nozzle doorat a location between the first pivot and one of the first end and thesecond end, wherein the actuator is configured to retract an actuatorrod to move the nozzle door towards a thrust reverse position.
 14. Anozzle as recited in claim 13, wherein the first end extends in aradially outward direction from the nacelle relative to a centerlineaxis of the gas turbine engine core and the second end extends in aradial inward direction in a thrust reverse position.
 15. A nozzle asrecited in claim 13 wherein movement of the nozzle door changes avariable cross-sectional area associated with the fan bypass passage toinfluence the bypass airflow.
 16. The nozzle as recited in claim 13,wherein the nozzle door is supported by a frame member, wherein theframe is pivotally secured to an aftmost end of the nacelle relative tothe bypass flow.
 17. The nozzle as recited in claim 13, wherein the lipis formed independent from the nozzle door and attached to the nozzledoor.
 18. The nozzle as recited in claim 13, wherein the lip is disposedat a non-parallel angle relative to the nozzle door when the nozzle dooris in a thrust reverse position.
 19. A nozzle for use in a gas turbineengine, comprising: a nozzle door having a first end, a second endopposed from the first end, and a first pivot on the door between thefirst end and the second end, wherein the nozzle door is supported by aframe member, wherein the frame member is arranged to be pivotallysecured to an aftmost end of a nacelle relative to a bypass airflow; alinkage connected with the nozzle door; and an actuator coupled with thelinkage, wherein the actuator is selectively operative to move thelinkage about a second pivot to in turn move the nozzle door about thefirst pivot between a plurality of positions to influence the bypassairflow through a fan bypass passage, wherein the nozzle door includes alip that extends from the nozzle door at a location between the firstpivot and one of the first end and the second end, wherein the actuatoris configured to retract an actuator rod to move the nozzle door towardsa thrust reverse position.
 20. The nozzle as recited in claim 19,wherein the linkage and the nozzle door rotate in the same direction.